A dredging system agitates the bottom sediment of a waterway to remove particles and oxygenate the water. The system diffuses air through a grid mounted on a waterway floor, raising particle clouds. The particle clouds are transported downstream by water currents while releasing dissolved oxygen throughout the water column. The method of particle removal and oxygenation is used in shallow depths, less than thirty-three feet (2 bars) with minimum favorable water currents of one-half to one knot. The grid is used for diffusion of air to alleviate hypoxic environments in depths less than sixty-six feet (5 bars).